The influence of Dilantin on collagen biosynthesis in gingival fibroblasts will be studied. Fibroblast cell lines will be established from patients receiving Dilantin who are either responders or nonresponders and from normal controls. The increased rate of collagen synthesis observed by other investigators will be compared to overall protein synthesis and quantitated. Further experiments will be directed toward determining whether an increase in transcription or translation is responsible for the increased rate of collagen synthesis. RNA will be labeled in culture and the half-life of the total messenger and the collagen mRNA populations will be determined. In addition, mRNA will be extracted from the fibroblasts and functional collagen mRNA quantitated by translation in a heterologous cell-free protein synthesizing system.